Parking Brake Malfunction - Contact Workshop!
 

I now have a "Parking Brake Malfunction - Contact Workshop!" message, continuous alarm sound and many flashing lights on the cluster.

I have had a problem with the connector getting damp and corroded in the past and it is is on the same left side but this time it looks OK and have cleaned anyway to no avail. Also did various adaptions in VCDS and this side never operates.

I have measured with a multimeter pins 1 and 4 from the caliper and there is 0 ohms resistance. I thought this was a good sign, so connected 12v jump leads from the car battery to these pins and just get a spark which ever way round. It does sound like something tries to move inside.
Now I am wondering if the centre two pins fire a relay or something?
Does anyone have any idea how to test further?

Thanks.

0 ohms is a dead short, have you taken readings from the other side?

Thanks Delboy, I think that's a good idea will try that.
Thankfully it is stuck off rather than on.
The error occurred while driving at 40mph so I once would think it was just some sensor or wiring issue.

Two outer pins drive the motor , two inner pins current sensing maybe ??

Sounds like a duff caliper , did one on a Passat through the week , doing same as yours .... sparking when you try to drive it either way

Had the same problem last year. Turned out to be a faulty caliper.

Thanks for the tips. A bit of an update... I removed the two T30 screws holding the motor to the caliper, cleaned inside and outside with electrical cleaner and took inside the house and tested with a 12v power supply on the outer pins and the motor worked.

So I cleaned up the pins even more and bent the female ones in more to make them tighter. I took it back out and plugged it back in. The wires are not in great shape as 7years ago Audi London did a terrible repair.

I left the motor hanging loose and I removed Audi London's tape and connected a multimeter to the exposed wire so I could see it in the mirror and turned on ignition and VCDS and saw the voltage change from 0.000v
and went out and saw it was working. I cleared the code and it has gone and now have a new code: Pad not reaching disc or similar.

So the caliper is OK, but wiring isn't. I am now debating whether to cut out damaged 7-8mm and resolder all 4 with heat shrink or get a new connector and wiring kits, grommet inserts etc...

You may have to do an adaptation because the motor is in a different place, or did you get the error with the caliper off the carrier.

if you post a picture of the damaged wiring I can maybe point you in the right direction for suitable repair depending on the damage.

I have to repair and make cable for the sub all the time and they have to be water proof for thousands of meters water depth.

The sub has brake calipers ?? ;)

Yeah... have you never seen the size of the discs on a Rolls Royce nuclear reactor? They're massive... :ROFL:

Thanks chaps. Maybe a wiring problem after all?
After testing in the house, I thought at least the motor and gearbox is OK.
Maybe the hall sensors are duff but cannot test.
I tested the two outer thicker cables resistance again, it was ~2OHM - I think I made a decimal place mistake last time when the multimeter was on the beep function.

I have cut the two damaged thick cables and resoldered them using my last bit of environmentally-unfriendly lead solder. Resealed the connector. for now but want to get one in stock and replace if it goes again.
I removed the big o-ring from the caliper and cleaned it all up and put silicone grease on. Blob of Tamiya grease in the torx-style caliper drive shaft. All seems ok now.

Screws to remove the motor were really stiff and I had to use the mole-grips on a T30 torx. I used blue loctite on refitting screws as it keeps moisture out and de-oxidises (reducing agent). I wouldn't fancy using the torx tool that comes in the car's tool kit! Once the motor is removed, you can wind the park brake caliper plunger back with a T40 torx, that turns VERY easily.

I looked at greasing the EPB gearbox but is is in the motor half that you can't get into so just used a little silicone spray in the exposed side to keep the moisture at bay - I also think grease may damage the nylon toothed belt that is in there.

https://www.youtube.com/watch?v=tAGR1bd_8KQ

https://www.youtube.com/watch?v=ThVKwHJWTLA

For future reference, the loom-side connector part number is 1J0919231
http://www.aliexpress.com/item/Allro...582661446.html

although on this one the outer wires on the EPB are more like 4mm thick so will try and find the right type and replace them.